In a power window that raises or lowers a window glass of a vehicle by drive force of a raising/lowering motor, when the window glass is gradually closed by continuously setting an operational switch to be on in a closing direction, a foreign substance may be pinched between the window glass and a window frame.
A safety device is proposed, in which a detection device is provided for detecting a fact that the foreign substance is pinched between the window glass and the window frame, and when the device detects pinching, it reversely drive a motor to lower the window glass irrespective of a state of the operational switch. As such a pinching detection device in the safety device, a device is proposed, in which a capacitance sensor is provided at an upper edge of a window glass for detecting change in capacitance, and when a value of capacitance (voltage) decreases to a predetermined threshold value or less, it is determined that a human body partially contacts to the upper edge of the window glass, and accordingly the window glass is lowered (for example, refer to patent document 1).
However, capacitance between an electrode on the upper edge of the window glass and the window frame varies during raising operation of the window glass. Therefore, in a previous device in which a certain value of capacitance at which a window glass being raised is reversed is set as a fixed threshold value, false determination on pinching of a foreign substance (false lowering operation of a window glass) may occur. Moreover, capacitance varies during raising operation of the window glass, in addition, varies depending on a use situation (such as weather or aged deterioration). However, variation due to such a use situation is not considered in the past, which may cause false determination (false operation) as well. Furthermore, such capacitance has a property that it abruptly changes (increases) when the window glass reaches a region near a full closing position (top dead center). To avoid false determination that such abrupt change in capacitance is caused by pinching of a foreign substance, control was performed in the past, in which a particular sensor was provided at a window frame side, and when the sensor detected approach of the window glass, output of a capacitance sensor was neglected.
In the safety device that detects pinching by using capacitance, a capacitor electrode at a window glass side is continuously formed along an edge of a window glass that may form a gap with respect to a window frame during operation of a power window. When the gap to the window frame is formed at an upside and laterally two sides of the window glass, the capacitor electrode is continuously formed over the three sides (for example, refer to patent document 2).
In the above power window, during the raising operation of the window glass, the gap to the window frame is closed early at the lateral sides compared with at the upside. When the gap at each lateral side is closed, capacitance between the window glass and the window frame increases, therefore change in capacitance that may subsequently occur due to pinching becomes inconspicuous, leading to difficulty in detection of pinching.
In a method of determining presence of pinching through comparison between a capacitance value and a threshold value, even if capacitance exceeds the threshold value due to a cause other than pinching of a human body, pinching avoidance may be performed. This may induce, for example, the false operation that the window glass is reversed directly before the window frame is fully closed.
In the case that pinching is determined to occur from a fact that a detection signal value exceeds a threshold value, and the window glass is thus reversed, while sensitivity of pinching detection is improved with decrease in margin of the threshold value to a value of a detection signal of a sensor, false operation occurs more easily due to an external condition such as weather or air temperature, or fluctuation of sensor performance or the like.
Operation modes of the power window include an automatic mode where the window glass is reciprocated between an opening position of a window frame and a closing position thereof while avoiding pinching of a human body, and a manual mode where the window glass is reciprocated between the opening position of a window frame and the closing position thereof according to switch operation of a user. In the automatic mode, the window glass is raised or lowered by one-touch operation of a switch, and in the manual mode, the window glass is raised or lowered only while a switch is on (for example, refer to patent document 3).
In the case that a vehicle has a plurality of power windows, wherein a central operation switch is provided at a driver seat side, so that any of the plurality of power windows can be optionally operated from the driver seat, sufficient care needs to be taken to a condition of a different seat in switch operation.
That is, for example, when a passenger in a different seat rests its elbow on a belt line while a window is fully opened, unexpected raising of a window glass may cause panic of the passenger, in addition, when a body of the passenger rests against a window glass remaining half opened, since a dangerous situation may occur due to unexpected raising or lowering of the window glass, sufficient care needs to be taken.
In the safety device where pinching is detected using capacitance between plate glass and a window frame, an electrode at a plate glass side is deposited onto an edge portion of the plate glass (for example, refer to patent document 2). Plate glass for a door of a vehicle or the like is subjected to abrasion at the edge portion. The abrasion includes C-surface processing or R-surface processing using a diamond wheel (primary processing), and finishing (secondary processing) using a chamfering wheel (for example, refer to patent document 4).
While either of the abrasion and the electrode deposition is processing to the edge portion of the plate glass, kinds of processing are completely different from each other, leading to a problem that they must be performed using different apparatuses and steps from each other.
Patent document 1: JP-A-2002-46468
Patent document 2: JP-A-10-110574
Patent document 3: JP-A-7-317430
Patent document 4: JP-A-2002-160147